Improvement in ore-concentrators



zs th F' E. MILLS; ee s Shee'pl.

oRE-coNcENTRAToRs.

Patent 30,183,319. jgct. 17, 187s.

UNITED STATES PaTENT @Erreag FRANCIS E. MILLS, OF VIRGINIA CITY, NEVADA.,

IMPROVEMENT IN ORE-co'NcENTRAToRs.

Specicationforming part of Letters Patent No. 183,319, dated October 17, 1876; application filed Y August 16, 1876.

To all whom it may concern Be it known that I, FRANCIS E. MILLS, of Virginia City, in the' county of Storeyand State of Nevada, have invented a new and Improved Ore-Concentrator, of which the following is a specitication: y

rlhis improvement is designed especially to take the place ol' the long lines of blanket-tables now so generally employed on the Pacific coast in concentrating tailings from quartzmills, but is also to be used as a substitute for all that class of inclined tables, Whether blanketed or plain, stationary or rotating, where the metallic particles, after having been deposited upon the surface of the table from a thin sheet of ore-pulp flowing over it for a time, are washed by the admission of clear water, and then swept off either with brooms or jets of water.

vIn order to do much work, all concentrating-tables of the class referred to must have a large surface; and one objection to those in present use, (which my invention is designed to remedy) is, that when working on a large scale, this surface being spread out either on' a single plane, covering` sometimes many thousand square feet, or 011 several large planes, side by side, they occupy so much ground-room that it is impracticable, or Very expensive, to house them or to operate them in severe weather.

rlhe process of sweeping off the ore-deposit with ordinary brooms, which is employed on tables of any great lengt-h, besides being laborious and slow, is very destructive to the vblanket or other fabric with which they are covered.

The objection to the stationary side jet-pipe or revolving sprinkler, which, instead of the ordinary broom, is advantageously lused on some shorter tables, is that the reach of its effective sweep is too limited and in order to sweep any considerable distance it must be placed 'so high above the table that the force ofthe jet is greatly abated by the resistance` ofthe atmosphere, and much of it is converted into mere spray, necessitating a much larger expenditure of clear water than would be required if the jets could issue from their oriflces close to the surfaces ofthe table.

Another objection to the present mode ot' using concentrators of this class, especially 011 the Pacific coast, is that in the absence of any convenient attachment for classifying the sands as they flow, the coarse and the tine are all comming-led, and flow at the same time over the same table, occasioning a great loss of the finely-comminuted ores 5 for where the current is kept sufficiently strong, either by its volume or steepness, to carry off the coarsest sands, the lighter particles of metal can not find a lodgment on the surface of the table or cloth. A,

The objectl of my invention is to remedy each and all ofthe objections referred to;l and it consists, first, in arranging inclined tion 5 also, to insure a proper and easy clasv sification ot' the sands as they flow upon the respective tables, and. thus secure a larger percentage ot' the ore 5 secondly, connecting with such vertical arrangement of tables a classifying head-box, F,'by means of which the sands naturally grade themselves as they flow out upon the ditferent tables, the coarsest and heaviest particles liowing over the bottom tables, the finest and lightest over the top table, and grains of intermediate grades of neness over the intermediate tables, the,

inclination of each table, respectively, and the volume of current, being adapted to the grade ot' sand it carries; thirdly, in employing on all stationary tables a traveling Water-broom, which, consisting of a perforated pipe or gang of perforated pipes, extending acrossA the tables, and fed with clean water und-er pressure, is made to traverse the length of the table, ,Y close to the surface, (either on rollers or other' wise,) and sweep oft' the deposit in its progressv by jets through the perforations.

l make the gang-tables stationary, as represented in Figures 1, 2, and 3, rotating, as shown in Fig. 7, tilting, as represented in Fig. 8, or

in any other form desired; *but as the station-r timber.

ary form would generally be most useful in the mining .regions of this country where water is scarce, l now describe more particularly my usual mode of constructing them, reference being had to the accompanying drawings, making a part of this specilication, and in' wliieh Y Fig. 1 is a top view of a gang of tables. Fig. 2 is a. longitudinal section. t Fig. 3 is a cross-section. Figs. 4, 5, and 6 are detail views. Fig. 7 is a vertical section of airotary gang. Fig. 8 is a detail view of a tilting gano. Fig. 9 is'a detail view ofa water-broom.

ASimilar letters of reference indica-te corresponding parts.

The general arrangement will be seen in Figs. 1, 2, and 3, in which A A A are the tables. In order to permit the sweeping of all the tables in the gang at one operation, it becomes necessary to leave a clear space between each, from end to end, for the water- -broom to travel in.

Any vertical supports between the tables would interfere with this movement. For this reason 'I generally construct them as follows: Supposing the gang to consist of twelve (12) tablesn superposition, each table to be four (4) feet wide by forty (40) feet long, I plant two heavy timbers, B B, about ifty feet'long, side by side, parallel, and frame the endstogether about `four (4) feet apart, giving them lan inclination loiigitudinally of about halfvan' inch to the foot. Say tive (5) feetfrom the ends of each I frame in strong upright posts C (l, about (5%) five and a half feet high; or, in place of wood, I make these posts of iron, with a thick broad ange for a base, which I bolt firmly to the Through these posts, longitudinally with the gang, I insert strong iron rods 4D I) D, one inch in diameter, one over another,`

with a space of from three to four inches (vertically)between each, giving to each rod, respectively, the proper inclination for its table, as hereafter explained. They are then made taut by heavy nuts a'nd washers on the ends. Ihese tense rods support the table. I make the floor of boards, say, one and one-fourth `through the box Vfrom top to bottom, which` may be left up, say, from one totwo inches inch thick, laid transversely on the rods, with grooves or rabbets cut in the under side of each to t the rods. To prevent the rods from either spreading or approaching each other, and to guardagainst any sagging ofthe boards in tlie'center, I connect the rods transversely by rigid metal bars E E E, a few feet apart, laying the upper surface ilnsh with thesurface of the boards. vThe narrow list on the sides of each table is held on with metal clamps, in order that it may be easily removed i ways, specified as follows: First,in case the run- ,ning pulp is very thick, and there is not clean `water at command to dilute it, I close down and replaced when renewing the cloth covering. y n i The tables may be made of any width and length desired. If more than four or five feet wide, theyshould have a third line of supporting-rods extending longitudinally through the center; but, for convenience of working, it is better to have each gang not to exceed four o'rfive feet in width by thirty to fifty in length,

i spectiyel y.

yright quantity of pulp to each table.

Ais ten or twelve times wider at the top. `iiare of the box is principally on the side next possible, to avoid lance below.

and, when more surface is desired, increase the number of tables in the gang rather than their width.

For finelv-pulverized ore or tailings, I give to uthe lower table an inclination of threefourths of an inch to one and one-halt' inch to the foot, and to the upper one about one-eighth pulverized ores and tailings from quartz-mills,

heavy duck for the bottom table and tine cotton sheeting for the upper one make about the right kind of surface, with fabric of varyingdegrees of roughness for those interniediate. At the head `of this gang of tables, with its face pressing against the upper' end of each table, is the classifying-box F, into which the `main stream of pulp is first fed, and from which it Hows out upon the head of the tables through horizontal rows of aperf tures cut in its face just above each table, re-

This box is, made eight orten inches higher than the gang ot' tables, to prevent the pulp spreading over as 1t falls into it from the main conduit.

The proper size of the `apertures over each l table will depend upon the coarseness of the l ore, but may be varied to suit different condi-4 tions by the adjusting-slides G, Figs. 1 and 2, which can always be regulated to admit the This classifying-box is quite narrow at the bottom, (not exceedingan inch or t'wo in width,) but the tables ,the other side being `nearly vertical. This ilare insideis not uniform from `topto bottom, but increases rapidly toward `the top, as represented in Fig. 2, detail view.

H, Fig. 2, is a sliding partition, extending from the bottom, to permit the passage of pulp or water underneath it, or may be pushed down upon the bottom, cutting off all communication between the two compartments of the box. l is simply a thin metal guard, extend` `ing down intothe box eight or ten inches, to give1 initial direction to the entering grains of san. l

I use this classifying-box in either of three the sliding partition H and feed the pulp in `just forward of it at J. (the box being kept `full up to the lille X.) The drop from the inain `conduitinto this box `should be as smallas' any detrimental disturb` The' ' Fed in this manner, the operation ofthe box is this: The box being kept full, there is the vertical tendency of the grains by gravitation,

'ployed'on `the gang of stationary tables hereand also a lateral tendency by the draft of the currents through the side apertures. Acted upon by these two forces, the coarsest grains of vboth sand and metal, lbeing least diverted from their vertical course, will reach the lowest aperture and iiow out upon thebottom ta.

ble. The nest particles, in the 4nature of slime, having but littleitendency to descend through the mass, remain at the top, and pass out upon the uppertable or tables, while grains of intermediate degrees of gravitatng power will mainly be drawn through apertures of corresponding distance from the bottom.

Second mode: clear water at command, I raise the sliding partition H about one inch, or less, from the bot-tom, and, while still admitting the thick pulp at J, let a stream of clear water flow into the compartment K, being careful so to adjust the open space under the partition that the head of clear water standing in thateompartment shall preponderate sufficiently over that of the pulp to produce a slight upward current of the latter in the lower portionof the box. A

Third mode: If the pulp, as it comes from the main conduit, should be already greatly diluted with water, I raise the partition-slide somewhat higher, and feed it all in at K. In f that case all the sands reach the dischargingapertures with an upward current, diminishing in velocity with the increasing width ofthe box as it ascends. Y f

In either of these described modes of using the box the classification of the sands on the respective tables will be sufficiently thoroughfor practical working, provided proper attention be given to secure uniformity of standing head in the box and the proper volume of-low over each table. I

Inside the box, forward of the partition, the box is partially .filled with wedge-shaped blocks 'L L L, extending transversely'through it from top to bottom, to narrow the channel downward, and prevent any dead watenin the lower portion of the box, in which sand would be liable to settle. Outside the box, in front of eachv row of discharging-apertures, is fixed a thin metal dash-board,'which checks the spouting pulp and spreads it evenly upon the head of the table.

Although it is most con-venient to place the classifyiugbox against the head of the gang, with the aperturesdischarging directly upon the tables, yet, if the gang bewide, it is sometimes better to place this box a fewfeet back, make it quite narrow transversely of the gang, with a single large aperture for each table, instead of a row of apertures, and attach a fan-shaped trough to each apertureleading to its corresponding table. In that case I place the dash -board designedv to break the spouting force of the pulp inside this trough,

whichl spreads vand drops it quietly upon the head of the table.

The traveling water-broom: rThis, when einin'before described, consists of a verticalv gang "of small horizontal perforated pipes, P P P, ,set rigidly in a frame restingon the wheels O 0. These'pipes are supplied with clear water `through the hose M, which' is coiled on the reel ordrum N. This hose connects, by means The perot' tables, one over each table, as seen in Fig.

- .11. The frame which holds the pipes, 'and If there is an abundance of tally vacross the top of the gang of tables, 'with arms R R hanging down vertically on which rests lupon the wheels O, lies horizoneach side nearly to the bottom table. The

horizontal part S of this frame, also one of the hanging armsR, is hollow, constituting a receiver of the water from the hose, and into i which both the hose and the perforated pipes open. The opposite hanging arm R is simply lto support the closed ends of the pipes exattach similar valves or stop-cocks to-each ot' the perforated pipes near their junction with thereceiver, to regulate the amount ot' clear water to be supplied to each table, respectively.

The wheels on which the entire weight ot' this traveling water-broom rests are provided .The hose-drum should be made as light as consistent with the requisite strength, but should have large circumference. I place this hose-drum over the-lower end of the gang of tables, the under side being ve or six inches higher than the top of the rails.v Over the upper end of the gang, just forward of the classifying-box, I tix a grooved pulley, V, about one foot in diameter, its lower edge being the same distance above the rails as that of the hose-drum. Passingover this pulley and drum is an endless chain, W, which is also attached, by a hook or otherwise, to the frame of the water-broom at Y, near the point where the hose enters the receiver. This pulley is turned by hand by means of the cranky Z. f I 4In practice, both the druml and pulley may be suspended from the timbers of the building, and not attached to the frame-work of the tables.

Fixed transversely between the rails, and, say, three or four feet apart, are placed rollers a c u', to support any slack of the hose as it travels back and forth. The size ofthe pipes P P will depend upon the width of the tables, andthe size of the hosezand receiver upon the width and number of-tables in the gang. If

the tables are only four or ve feet wide, ten or twelve in a gang, I make the diameter of the pipes about one inch (or less) inside, that of the hose and receiver being from three to three and one-half inches. The perforations in the pipe may be in the form of one row of small round holes, say one-sixteenth of an inch in diameter, (those for the lower tables being somewhat larger,) or very fine horizontal slits, half an inch long, placed in two rows, the slits slightly overlapping each other. These perforations are a little forward of the bottom of each pipe, in such a position that the jets of water issuing therefrom shall strike the plane of the table at an angle of about forty-five degrees.

.The operation ofthis water-broom is as follows: The position of the broom while the pulp is owing over the tables is at the head ofthe gang, the hose being uncoiled and resting upon the line `of rollers, and each pipe reposin g across its respective table, just under the I'ow of discharging-apertures in the headbox. When the washed deposit on the tables is ready for the sweeping, the valve T is opened. The water jets through the perforations, and the crank being turned appropriately, the hose is slowly coiled upon the drum, causing the broom to travel with the same motion down the length of the gang, each pipe sweepf ing off the deposit on its own table as it moves along. The valve of the receiver is then closed, the motion reversed, and the broom run back to its former position at the head of the tables. If preferred, the gang may` be made much narrower and shorter, say only two feet wide by twenty feet long, and the inclined floor made of thin sheets of metal laid not more than` one inch apart, the sweepingpipes being proportionately small. This, if the gang were four andone-half feet high, would give a working-surface of nearly two thousand square feet, and occupy but forty square feet of ground-floor. C 1

Haring thus particularly described the construction and operation of my invention in its best form when applied to stationary rectangular tables, I will briey point out some modincations of the same as applied to other forms and conditions.

In all cases where there'is an abundance of clear running water to be had convenient to V the works, instead of the stationary rectangular tables just described, I-construct the gang `in the form of a circle, and give to it a slow rotating movement. In this case the inclined tables are framed one over another, on one vertical shaft, all sloping toward the center, but with varying degrees of inclination, as represented in Fig. 7 in the accompanying drawing, in which A1 Al A1 are the tables. Each table is supported by a set of strong arms, C' C' C', framed into the large vertical shaft D. In the central portions of the wheel these arms are strong and deep, rest upon each other, and are firmly bolted together, to make the entire` frame as rigid and unyieldin g as possible; but that portion of each armimmediately under the table is considerably smallerand tapers to the end, leaving a clear space between each table over the whole surface.

In constructing a rotating gang, consisting of ten or twelve tables, I give to the upper one, which receives the slimes, an inclination of about one-eighthof an inch to the foot; to the next, three-sixteenths, and so on, increasing the inclination more rapidly toward lthe lowest, which may fall as much as one and one-halfinch to the foot, if some of the material to be concentrated is coarse. In a gang of that number of tables, it is not essential that they all vary in inclination. Two or more tables carrying the same class of sands may he parallel. The pulp is fedonto this rotating gang from the outside or periphery, `at several points in the circle, there being a classifying-box, F, at each feeding-point, (substantially like that described for the stationary gang,) through, which the' sands classify themselves in flowing out upon their respective tables. For sweeping oit' the deposit from this rotating gang-table, I use vertical gangs of perforated pipes under pressure, placed at the proper distances around the wheel, one pipe in every gang reaching diagonally across each table. Other appliances connected with the working, being similar to those employed in operating rotating tables now in use, it is unnecessary to describe in this specification.

There is another mode in which I contemplate using the gang-table and head-box in localities where-clear water is too scarce to run the traveling water-broom. It is represented in Fig. 8. In `this forml place the shelf-like inclined plates closer together than in any heretofore described, with the sides inclosed, and the entiregang (which is only eight or ten feet long) so nearly balanced` on the horizontal pivot or bearings X that,on washing down, the head end of the gang may be tilted up clear of the head-box F, and the deposit swept oi' 4all the plates at once by a douche from a vessel of water, w, overhanging the tilted end ofthe gang. i i r e Fig. 8 represents in vdotted lines ythe position of this gang and hox while working, and in full lines its position when tilted to receivethe douche. The entire end ofthe gang is only about l one and one-half to two feet square by nine feet long, andthe thin plates about` halt' an inch apart. The head-box stands on small wheels like casters, so lthat it may be readily drawn back a little, then pushed up against the head of the gang at each tilting operation.

Another form of the traveling broom I do not confine the use of the traveling broom to gang-tables, but apply it also to all forms of single stationary tables, whether rectangular or circular. f

When applied to a broad rectangular table, spread out on a single plane, Igenerally construct the broom in the manner represented in Fig. 9. In this form the broom does not move on rollers or wheels, but, being suspended by the arms e? e2 toa horizontal shaft, f2, placed high above the table, it swings forw ard and back over the plane of the table, sweeping oil' the deposit in its forward movement by jets through the perforatious. This form being quite desirable on some tables already constructed, I will describe it more particularly.

Fig. 9 is a vertical elevation of this single table and broom, in which A2 is the table, and P2 is an end view of the water-broom, which consists of a triangular-shaped pipe, perforated at its lower acute angle, extending trans versely over the table, suspended by the arms c2 e2 to the horizontal shaft f2, this shaftbe ing placed on bearings about twelve feet (more or less) above the table.

S is a hollow receiver or pipe, attached rigidly to the arm e, its lower end connecting with the broom P, and its upper end connecting, by means of a turningjoint at Q, with a stationary pipe, in line with the axis ofthe shaft. This latter pipe communicates with a reservoir of clear water.

The pipe S2 is furnished with a globe-valve nearitsjunction with the broom.' If the table is very wide, the shaft (which is small) should have two or more bearings toward the center in addition to those at the ends, and 'at each bearing an additional arm should extend down and embrace the broom, in order to stlffen and support it through its entire length.

The weight of the arms, broom, and pipe S2, filled with water, is counterpoised by the balancing-weight K, placed on the opposite side of the shaft, to insure its equilibrium at all points while working. If the arm be twelve feet long, the broom will sweep thirty feet in length of tables at one movement. The line over which the shaft lies should be one-third the length of the table from its head.

, When constructed in this form, the traveling broom may be moved over` the table by the operator taking hold of a sliding knob inserted in the arm at l2, and walking along with it forwardand back; or light segment-gearing may be attached to the arm e2, and the broom operated with a crank. The dotted lines in Fig. 9 show the position of the broom at the extremes of its movement.

Having thus described my invention, I claim as new and desire to secure by Letters Patent- 1. An ore, tailings, or slime concentrator,

'consisting essentially of a vertical series of inclined tables, plates, or floors, framed one over another, and sloping` in the same direction, provided with feeding-apertures of different heights, and combined with a waterspouting device for sweeping the whole series simultaneously, substantially as Aand for the purpose hereinbefore described.

2. The stationary gang-table A A A, Figs. l and 2, combined with the traveling waterbroom P P P P, Figs. l and 2, constructed and operating substantially as described.

3. In combination with a series of inclined plates or tables, framed one over another, the classifying head-box F, either with or without the partition H, constructed and operating substantially as and for the purpose hereinbefore set forth.

FRANCIS E. MILLS.

Witnesses: l

ALPHA DAVIS, IRA S. PARKE. 

